Microstructure of a Y2Ba2Cu3O7-Σ superconductor pellet prepared by shock consolidation

Author(s):  
R. F. Antrim ◽  
J. Marti ◽  
Z. Iqbal

R&D in high Tc superconductors encompasses two broad areas, namely, 1) synthesis and characterization of high Tc superconducting powders and 2) consolidation of the powders into useful parts. In the latter area, techniques such as thin film deposition, high temperature sintering of the powders and continuous casting are being pursued by various groups. Another technique which could prove useful in the fabrication of larger pieces is that of shock compaction. In this approach, explosives are used to propel a piston, resulting in a shock wave which leads to high pressure- high temperature consolidation of the powder. In this report we examine the microstructure that results when a superconducting powder was consolidated into a pellet using the shock-loading technique.The nominal composition of the starting powder was Y1Ba2Cu3O7δ (“123”). Explosives were used to create a shock-wave with an estimated peak pressure of 60 GPa and temperatures of about 800°C.

1989 ◽  
Vol 169 ◽  
Author(s):  
K. Wasa ◽  
H. Adachi ◽  
K. Hirochi ◽  
Y. Ichikawa ◽  
K. Setsune

AbstractBasic thin film deposition processes for the high-Tc superconductors of Bi-systems are described. There appear several superconducting phases including the low-Tc phase Bi2Sr2Ca1 Cu2Ox and the high-Tc phase Bi2Sr2Ca2Cu3Ox. Thin films with these superconducting phases are synthesized by a selection of the substrate temperature Ts during the deposition : the high-Tc phase with Tc=100K is synthesized at Ts>800 °C; the low-Tc phase with Tc=80K, at Ts<600°C. However, these films often comprise show structure comprizing the different superconducting phases.The close control of the superconducting phase has been achieved by the layer-by-layer deposition in the atomic layer epitaxy process.


Author(s):  
R. F. Schneidmiller ◽  
W. F. Thrower ◽  
C. Ang

Solid state materials in the form of thin films have found increasing structural and electronic applications. Among the multitude of thin film deposition techniques, the radio frequency induced plasma sputtering has gained considerable utilization in recent years through advances in equipment design and process improvement, as well as the discovery of the versatility of the process to control film properties. In our laboratory we have used the scanning electron microscope extensively in the direct and indirect characterization of sputtered films for correlation with their physical and electrical properties.Scanning electron microscopy is a powerful tool for the examination of surfaces of solids and for the failure analysis of structural components and microelectronic devices.


Author(s):  
E. L. Hall ◽  
A. Mogro-Campero ◽  
L. G. Turner ◽  
N. Lewis

There is great interest in the growth of thin superconducting films of YBa2Cu3Ox on silicon, since this is a necessary first step in the use of this superconductor in a variety of possible electronic applications including interconnects and hybrid semiconductor/superconductor devices. However, initial experiments in this area showed that drastic interdiffusion of Si into the superconductor occurred during annealing if the Y-Ba-Cu-O was deposited direcdy on Si or SiO2, and this interdiffusion destroyed the superconducting properties. This paper describes the results of the use of a zirconia buffer layer as a diffusion barrier in the growth of thin YBa2Cu3Ox films on Si. A more complete description of the growth and characterization of these films will be published elsewhere.Thin film deposition was carried out by sequential electron beam evaporation in vacuum onto clean or oxidized single crystal Si wafers. The first layer evaporated was 0.4 μm of zirconia.


Ceramics ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 108-120
Author(s):  
Simone Barbarossa ◽  
Roberto Orrù ◽  
Valeria Cannillo ◽  
Antonio Iacomini ◽  
Sebastiano Garroni ◽  
...  

Due to their inherent chemical complexity and their refractory nature, the obtainment of highly dense and single-phase high entropy (HE) diborides represents a very hard target to achieve. In this framework, homogeneous (Hf0.2Nb0.2Ta0.2Mo0.2Ti0.2)B2, (Hf0.2Zr0.2Ta0.2Mo0.2Ti0.2)B2, and (Hf0.2Zr0.2Nb0.2Mo0.2Ti0.2)B2 ceramics with high relative densities (97.4, 96.5, and 98.2%, respectively) were successfully produced by spark plasma sintering (SPS) using powders prepared by self-propagating high-temperature synthesis (SHS). Although the latter technique did not lead to the complete conversion of initial precursors into the prescribed HE phases, such a goal was fully reached after SPS (1950 °C/20 min/20 MPa). The three HE products showed similar and, in some cases, even better mechanical properties compared to ceramics with the same nominal composition attained using alternative processing methods. Superior Vickers hardness and elastic modulus values were found for the (Hf0.2Nb0.2Ta0.2Mo0.2Ti0.2)B2 and the (Hf0.2Zr0.2Ta0.2Mo0.2Ti0.2)B2 systems, i.e., 28.1 GPa/538.5 GPa and 28.08 GPa/498.1 GPa, respectively, in spite of the correspondingly higher residual porosities (1.2 and 2.2 vol.%, respectively). In contrast, the third ceramic, not containing tantalum, displayed lower values of these two properties (25.1 GPa/404.5 GPa). However, the corresponding fracture toughness (8.84 MPa m1/2) was relatively higher. This fact can be likely ascribed to the smaller residual porosity (0.3 vol.%) of the sintered material.


Author(s):  
Gunter Heymann ◽  
Elisabeth Selb ◽  
Toni Buttlar ◽  
Oliver Janka ◽  
Martina Tribus ◽  
...  

By high-pressure/high-temperature multianvil synthesis a new high-pressure (HP) phase of Co3TeO6 was obtained. The compound crystallizes in the acentric trigonal crystal system of the Ni3TeO6-type structure with space group R3...


2020 ◽  
Vol 75 (6-7) ◽  
pp. 597-603
Author(s):  
Birgit Fuchs ◽  
Hubert Huppertz

AbstractThe non-centrosymmetric scandium borate ScB6O9(OH)3 was obtained through a high-pressure/high-temperature experiment at 6 GPa and 1473 K. Single-crystal X-ray diffraction revealed that the structure is isotypic to InB6O9(OH)3 containing borate triple layers separated by scandium layers. The compound crystallizes in the space group Fdd2 with the lattice parameters a = 38.935(4), b = 4.4136(4), and c = 7.6342(6) Å. Powder X-ray diffraction and vibrational spectroscopy were used to further characterize the compound and verify the proposed structure solution.


2003 ◽  
Vol 33 (1) ◽  
pp. 123-127 ◽  
Author(s):  
J.A.S. da Matta ◽  
R.M.O. Galvão ◽  
L. Ruchko ◽  
M.C.A. Fantini ◽  
P.K. Kiyohara

2013 ◽  
Vol 37 (3) ◽  
pp. 873-883 ◽  
Author(s):  
Tsai-Cheng Li ◽  
Rwei-Ching Chang ◽  
Yen-Choung Li

Silver conductive thin films deposited on glass and polyimide substrates by using ink jet printing are studied in this work. Characterization of the printed thin films and comparison with sputtered films are investigated. The micro texture, residual stress, adhesion, hardness, optical reflectance, and electric resistance of the thin films are discussed. The result shows that the ink jet printing has the possibility to replace sputtering in thin film deposition, especially for the polymer substrates.


2016 ◽  
Vol 18 (36) ◽  
pp. 25329-25341 ◽  
Author(s):  
Karol Palczynski ◽  
Philipp Herrmann ◽  
Georg Heimel ◽  
Joachim Dzubiella

Mass transport processes of conjugated organic molecules (COMs) on inorganic surfaces are essential elements in thin film deposition for hybrid optoelectronic devices.


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